6.5
MEDIUM CVSS 3.1
CVE-2026-59920
Netty: STOMP CONNECT Frame Header Injection
Description

Netty is an asynchronous, event-driven network application framework. In versions prior to 4.1.136.Final and 4.2.16.Final, Netty's STOMP encoder ( StompSubframeEncoder ) does not escape or validate header values in  CONNECT  and  CONNECTED  frames, so raw newline ( \n ) characters in a header value are written directly to the wire, allowing an attacker who controls a header value to inject additional STOMP headers. This happens because the encoder intentionally skips escaping for CONNECT/CONNECTED frames per the STOMP 1.2 specification but never rejects the raw newlines, and since a broker parses each line as a separate header, an attacker controlling a value such as a user-supplied login or passcode can overwrite connection parameters or add authentication/role headers to bypass authentication or escalate privileges (the actual impact is broker-dependent). The issue is fixed in versions 4.1.136.Final and 4.2.16.Final.

INFO

Published Date :

July 29, 2026, 6:16 p.m.

Last Modified :

July 29, 2026, 8:17 p.m.

Remotely Exploit :

Yes !
Affected Products

The following products are affected by CVE-2026-59920 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Netty netty
CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 134c704f-9b21-4f2e-91b3-4a467353bcc0
CVSS 3.1 MEDIUM [email protected]
CVSS 3.1 MEDIUM MITRE-CVE
Solution
Update Netty to a patched version to fix STOMP header injection vulnerabilities.
  • Update Netty to version 4.1.136.Final or later.
  • Update Netty to version 4.2.16.Final or later.
  • Ensure STOMP header values are properly validated.
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2026-59920.

URL Resource
https://github.com/netty/netty/security/advisories/GHSA-3g8r-4pfx-jmfh
https://github.com/netty/netty/security/advisories/GHSA-3g8r-4pfx-jmfh
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-59920 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-59920 weaknesses.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-59920 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-59920 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0

    Jul. 29, 2026

    Action Type Old Value New Value
    Added Reference https://github.com/netty/netty/security/advisories/GHSA-3g8r-4pfx-jmfh
    Added SSVC {'id': 'CVE-2026-59920', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'poc'}, {'automatable': 'no'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2026-07-29T19:01:13.468486Z'}
  • New CVE Received by [email protected]

    Jul. 29, 2026

    Action Type Old Value New Value
    Added Affected [{'vendor': 'netty', 'product': 'netty', 'versions': [{'status': 'affected', 'version': '< 4.1.136.Final'}, {'status': 'affected', 'version': '>= 4.2.0.Final, < 4.2.16.Final'}]}]
    Added Description Netty is an asynchronous, event-driven network application framework. In versions prior to 4.1.136.Final and 4.2.16.Final, Netty's STOMP encoder ( StompSubframeEncoder ) does not escape or validate header values in  CONNECT  and  CONNECTED  frames, so raw newline ( \n ) characters in a header value are written directly to the wire, allowing an attacker who controls a header value to inject additional STOMP headers. This happens because the encoder intentionally skips escaping for CONNECT/CONNECTED frames per the STOMP 1.2 specification but never rejects the raw newlines, and since a broker parses each line as a separate header, an attacker controlling a value such as a user-supplied login or passcode can overwrite connection parameters or add authentication/role headers to bypass authentication or escalate privileges (the actual impact is broker-dependent). The issue is fixed in versions 4.1.136.Final and 4.2.16.Final.
    Added CVSS V3.1 AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N
    Added CWE CWE-93
    Added Reference https://github.com/netty/netty/security/advisories/GHSA-3g8r-4pfx-jmfh
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.